Anaplastic thyroid carcinoma: long-term survival after radical surgery

Anaplastic thyroid cancer: a review of epidemiology, pathogenesis, and treatment

Anaplastic thyroid cancer (ATC) is an uncommon malignancy of the thyroid. Only 1-2% of thyroid cancers are anaplastic, but the disease contributes to 14–50% of the mortality with a median survival of 3 to 5 months. Most patients diagnosed with this disease are 65 years of age or older. The incidence of anaplastic thyroid cancer is decreasing worldwide. Most patients present with a rapidly growing neck mass, dysphagia, or voice change. We performed a comprehensive literature search using PubMed focusing on the treatment of anaplastic thyroid cancer including historical review of treatment and outcomes and investigations of new agents and approaches. A total of sixteen chart review and retrospective studies and eleven prospective studies and/or clinical trials were reviewed. The current standard therapeutic approach is to consider the disease as systemic at time of diagnosis and pursue combined modality therapy incorporating cytoreductive surgical resection where feasible and/or chemoradiation either concurrently or sequentially. Doxorubicin is the most commonly used agent, with a response rate of 22%. Several new agents are currently under investigation. Referral of patients for participation in clinical trials is needed.

Anaplastic Thyroid Carcinoma: Biology, Pathogenesis, Prognostic Factors, and Treatment Approaches

BACKGROUND

Anaplastic thyroid carcinoma (ATC) is one of the most aggressive solid tumors known to affect humans and carries a dismal prognosis. Our primary aim was to review its epidemiology, biology, risk factors, and prognostic indicators. We also reviewed the individual and combined roles of surgery, radiotherapy, chemotherapy, and newer therapeutic options in the management of ATC.

METHODS

An extensive literature review was conducted to include all published reports on ATC. The changing trends in the management of anaplastic thyroid cancer were analyzed to summarize the current practice of management of ATC.

RESULTS

Although ATC is rare, there has been a decline in its incidence worldwide. ATC accounts for more than half of the 1200 deaths per year attributed to thyroid cancer. Long-term survivors are rare, with >75% and 50% of patients harboring cervical nodal disease and metastatic disease, respectively, at presentation. ATC can arise de novo or from preexisting well-differentiated thyroid cancer. Surgical management has shifted from tracheostomy only for palliation to curative resection when possible. Tracheostomy is performed for impending obstruction rather than for prophylaxis. Radiotherapy has evolved from postoperative administration only to preoperative treatment, combining preoperative and postoperative treatment and using higher doses, along with hyperfractionating and accelerating dose schedules. Chemotherapy has changed from monotherapy to combination therapy, and newer drugs such as paclitaxel show promise. Similarly, novel angiogenesis-inhibiting agents are currently being used, with early reports of some benefit.

CONCLUSIONS

Despite multimodality approaches, ATC still carries a dismal prognosis. This should provoke innovative strategies beyond conventional methods to tackle this uniformly lethal disease.

Anaplastic thyroid carcinoma

BACKGROUND

Anaplastic thyroid carcinoma (ATC) is rare but is one of the most aggressive human malignancies. Several prognostic factors have been observed in patients with ATC, and some experts advocate aggressive multimodal therapy in selected patients. However, it is unclear whether such an approach significantly improves survival. The authors analyzed prognostic factors and treatment outcomes in patients with ATC reported in the National Cancer Institute's Surveillance, Epidemiology, and End Results data base.

METHODS

The cohort consisted of 516 patients with ATC reported to 12 population-based cancer registries between 1973 and 2000. Demographic, pathologic, and treatment data were used for univariate and multivariate survival analyses.

RESULTS

The mean patient age at diagnosis was 71.3 years, and there were 171 men and 345 women. Eight percent of patients had intrathyroidal tumors, 38% had extrathyroidal tumors and/or lymph node invasion, and 43% of patients had distant metastasis. The average tumor size was 6.4 cm (range, 1-15 cm). Sixty-four percent of patients underwent surgical resection of their primary tumor, and 63% received external beam radiotherapy. The overall cause-specific mortality rate was 68.4% at 6 months and 80.7% at 12 months. Univariate analysis showed that age < 60 years, female gender, intrathyroidal tumor, external beam radiotherapy, surgical resection, and combined surgical resection of tumor and radiotherapy were associated with a lower cause-specific mortality. On multivariate analysis, only age < 60 years, an intrathyroidal tumor, and the combined use of surgical and external beam radiation therapy were identified as independent predictors of lower cause-specific mortality.

CONCLUSIONS

Although most patients with ATC had an extremely poor prognosis, patients < 60 years old with intrathyroidal tumors survived longer. Surgical resection with external beam radiotherapy for ATC was associated with lower cause-specific mortality.

[Anaplastic thyroid carcinoma. Our experience]

Anaplastic thyroid cancer ranks among the most lethal of all known human malignancies, and remains almost uniformly fatal. It represents approximately 1% of all thyroid carcinomas.

MATERIALS AND METHODS

A retrospective study was performed including all anaplastic thyroid carcinoma cases diagnosed in our institution between 1989 and 2000.

RESULTS

We collected 15 cases previously biopsied as anaplastic thyroid carcinoma. Three of them were treated with a curative intention; different palliative modalities were carried out for the remaining cases. None of the cases survived more than 1 year, and the median survival time was 3.5 months.

DISCUSSION/CONCLUSION

This study confirms the previously known aggressiveness of this neoplasm, in which the prognosis and evolution remain to be fatal.

Anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma (ATC) is a rare, highly aggressive tumor characterized by rapid growth that causes death soon after diagnosis. Optimal treatment is debatable because of inherent difficulties investigating a rare malignancy associated with a survival of only months. Nevertheless, there is evidence that a multimodality approach consisting of surgery, chemotherapy, and radiotherapy is the preferred approach when the disease is localized. Eradication by complete surgical resection with total thyroidectomy, although often not feasible, followed or preceded by concurrent doxorubicin-based chemotherapy and hyperfractionated external beam radiation has been occasionally used and can rarely be associated with long-term survival. Surgical extirpation with radical organ resection is associated with high morbidity, and, although an aggressive surgical approach is reasonable in selected patients, organ preservation should be the goal in a disease with high recurrence and death rates. Any modality used in isolation usually fails to control local and regional ATC. In otherwise healthy patients who can tolerate aggressive therapy, chemoradiation and surgery may also be warranted for palliating incurable disease in the neck, which can cause death by asphyxiation.

Does surgery improve the survival of patients with advanced anaplastic thyroid carcinoma?

Anaplastic thyroid carcinoma is one of the most lethal neoplasms, with poor prognosis being reported by most authors. The benefits of surgery for most cases of advanced disease remain controversial. In this study we asked the following question: Does surgical intervention alter outcomes for patients with advanced anaplastic thyroid carcinoma? Forty-six patients with advanced anaplastic thyroid carcinoma were analyzed. There were 20 patients with advanced localized disease (group 1), 15 of whom received surgery. Of the other 26 patients with evidence of distant metastases (group 2), 13 received surgery. For group 1 patients, the mean survival was 12.8 months versus 8.6 months in the surgical and nonsurgical subgroups (p = 0.46). For group 2 patients, the mean survival was 3.5 months versus 2.8 months in the surgical and nonsurgical subgroups (p = 0.72). These data suggest that surgery does not improve survival for patients with advanced anaplastic thyroid carcinoma. In conclusion, the mean survival showed no significant differences between surgical and nonsurgical patients (p = 0.43). This study suggests that surgical resection does not improve the survival of patients with advanced anaplastic thyroid carcinoma.

Completion thyroidectomy for differentiated thyroid carcinoma

Completion thyroidectomy is defined as the surgical removal of the remnant thyroid tissue following procedures less than total or near-total thyroidectomy. The extent of surgical management for differentiated thyroid carcinoma (DTC) is controversial. Although some authors advocate subtotal thyroidectomy with lower complication rates, total or near-total thyroidectomy and completion thyroidectomy have been defended by others because of the improved survival and lower morbidity that is comparable with subtotal thyroidectomy. In this study, the incidence of residual tumor and surgical complication rates in patients who underwent completion thyroidectomy were investigated. The medical records of 165 patients undergoing completion thyroidectomy for DTC were reviewed. Seventy-seven (46.6%) of these patients were found to have residual tumor in the remaining thyroid tissue. Anaplastic transformation developed in two of these patients. Permanent bilateral recurrent laryngeal nerve palsy occurred in three patients, and permanent hypoparathyroidism was seen in one patient. We recommend completion thyroidectomy as an efficient and safe method of surgical treatment with a low complication rate for DTC.

Anaplastic carcinoma of the thyroid: a clinicopathologic study of 82 cases

Anaplastic carcinoma of the thyroid accounts for about 10% to 15% of all thyroid carcinomas in the United States. Its lethality is evidenced by a 5-year survival rate of 3.6% and a median survival of 4 months. Rapid growth of a thyroid mass, frequently in a preexisting goiter, is the most common manifestation; the diagnosis should be considered and expeditiously pursued in all patients who present with this finding. Relatively favorable prognostic features seem to be unilateral tumors, a tumor diameter of less than 5 cm, no invasion of adjacent tissue, and absence of nodal involvement. For resectable lesions, thyroid lobectomy with wide margins of adjacent soft tissue on the side of the tumor seems to constitute a safe, appropriately aggressive surgical approach. Total thyroidectomy and radical neck dissection results in an increased complication rate and has no advantage over a more conservative approach. Radiotherapy, chemotherapy, immunotherapy, and combination radiotherapy and chemotherapy need further evaluation.